RU2730633C1 - Free-piston internal combustion engine with linear generator - Google Patents

Abstract

FIELD: machine building.SUBSTANCE: invention relates to power plants and can be used in automotive industry, heavy engineering and small power engineering, particularly in the form of auxiliary engines of transport mechanisms on mobile or portable electric power stations, electric welding machines, and so forth. Free-piston internal combustion engine with linear generator includes spark plugs, linear generator containing stator winding, gas distribution mechanism at cylinder ends, fuel-air medium supply manifold and exhaust gases collector. Proposed solution comprises four cylinders 2, 3, 4, 5, in the heads of which valves of timing mechanism 31, 32, 33, 34, 35, 36, 37, 38 and ignition contact are installed, with two pairs of coaxial pistons 6, 7 and 8, 9, rigidly connected with rods 10, 11, 12, 13 with pipe 14. Permanent magnets 15 are fixed on pipe outer side. Spherical bodies 21, 22 are installed on internal surface of pipe and shaft 18 installed by means of bearings 19 on housing 1 passes. At that, on the shaft side surface the sinusoidal profile continuous groove 20 is made. Disks 23, 24 of gas distribution mechanism with projections of control of valves 25, 26, 28, 29 and ignition contact 27, 30 are fixed on shaft ends.EFFECT: invention is aimed at improvement of engine reliability.1 cl, 7 dwg

Description

The invention relates to power plants and can be used in the automotive industry, heavy engineering and small-scale power engineering, in particular in the form of auxiliary engines of transport mechanisms in mobile or portable power plants, electric welding units, etc.

Known internal combustion engine (RF patent for invention No. 2451803, publ. 05/27/2012, bul. No. 5), which contains a working cylinder with an element that makes a reciprocating movement, and a mechanism for converting reciprocating movement into rotational movement, made in in the form of a rotating main drum with a guide, kinematically connected with an element moving back and forth. The mechanism for converting the reciprocating motion into rotational motion is equipped with an additional rotating drum and a synchronizing element. The additional drum is equipped with a guide, which is kinematically connected to the reciprocating element, and the synchronizing element is kinematically connected to both drums.

The disadvantage of the known engine is the complexity of its design and kinematic connections between the elements, which lead to low reliability of the engine.

Known free-piston engine adopted as a prototype (RF patent for invention No. 2500906, publ. 12/10/2013, bull. No. 34), made of at least one cylinder, inside which there are two oppositely mounted pistons with a rod containing spark plugs , linear generator, stator winding located on the cylinder, valve timing systems (mechanism) at the ends of the cylinder, fuel-air supply manifold and exhaust manifold. Each gas distribution system is made in the form of a hollow body installed at the end of the cylinder, inside which there is a bushing with inlet and outlet ports of the fuel-air mixture and exhaust gases, which have the ability to communicate, respectively, with the inlet and outlet manifolds, a driven flexible transmission wheel is made on the hub axis, and on the rod is made of a toothed rack, with which the gear wheel contacts the drive shaft, at the outer end of which the drive wheel of the flexible transmission is installed. A breaker connected to an electric candle is installed on the drive shaft. The engine is equipped with a control unit, a piston position sensor is installed on the drive wheel shaft.

The following set of prototype features coincides with the essential features of the invention: a cylinder inside which pistons with a rod, spark plugs, a linear generator, a stator winding, a gas distribution mechanism at the ends of the cylinder, a fuel-air supply manifold and an exhaust gas manifold are located.

The disadvantages of the prototype are the need for an electronic control system, which must control the movement of the pistons to ensure an optimal thermodynamic cycle, as well as the positioning of the pistons, preventing their collision with the cylinder heads, as well as the complexity of the design and kinematic connections between the elements, which in turn reduces the reliability of the engine.

The invention is aimed at improving the reliability of the engine.

A free-piston internal combustion engine with a linear generator includes spark plugs, a linear generator containing, a stator winding, a valve timing mechanism at the ends of the cylinder, an air-fuel supply manifold and an exhaust manifold. The proposed solution includes four cylinders, in the heads of which the valves of the gas distribution mechanism and the ignition contact are installed, with two pairs of coaxial pistons rigidly connected by rods to the pipe. Permanent magnets are attached to the outside of the pipe. On the inner surface of the pipe, spherical bodies are installed and a shaft passes through, mounted with bearings on the housing. In this case, a continuous sinusoidal groove is made on the side surface of the shaft. At the ends of the shaft, the disks of the gas distribution mechanism are fixed with valve control projections and an ignition contact.

The essence of the invention is illustrated by drawings, where FIG. 1 - longitudinal section of the engine; fig. 2 - section A-A (disk with projections of gas distribution and ignition); fig. 3 - section BB; fig. 4 - section B-B (cylinder head of the cavities of the gas distribution system); fig. 5 - the central part of the shaft with a continuous groove of a sinusoidal profile; fig. 6 - section T-G, Fig. 7 - cyclogram of engine operation.

A free-piston internal combustion engine with a linear generator contains a housing 1, inside which four cylinders 2, 3, 4, 5 are installed with the corresponding pistons 6, 7, 8, 9, forming two pairs of coaxial pistons 6, 7 and 8, 9. Pistons 6, 7, 8, 9 are rigidly connected by respective rods 10, 11, 12, 13 to the pipe 14. On the outer side of the pipe 14 permanent magnets 15 are fixed, located inside the stator 16 with the winding 17, forming a linear generator.

In the proposed engine, the role of positioning the pistons is performed by a shaft 18 passing inside the pipe 14 and mounted on bearings 19 on the housing. A continuous groove 20 of a sinusoidal profile is made on the side surface of the shaft 18 - two protrusions and two depressions. Spherical bodies are rolled along the groove 20 during engine operation, for example balls 21, 22 mounted on the inner surface of the pipe 14, limiting the stroke of the pistons 6, 7, 8, 9 by the upper and lower dead points. In this case, the shaft 18 itself acquires a rotational movement (one revolution in four strokes in each cylinder). The gas distribution mechanism includes discs 23 and 24 attached to the ends of the shaft 18. Disc 23 has valve control projections: inlet 25 and outlet 26, as well as an ignition contact 27. Disc 24 has valve control projections: inlet 28, outlet 29, as well as an ignition contact thirty.

The valves of the gas distribution mechanism are installed in the heads of cylinders 2, 3, 4, 5, respectively, inlet valves 31, 32, 33, 34 and exhaust valves 35, 36, 37, 38 with rods 39. Rollers 40 and spark plugs are installed at the ends of the rods 39 41, 42, 43, 44, respectively, for cylinders 2, 3, 4, 5. In the heads of cylinders 2, 3, 4, 5, a manifold 45 for the passage of the combustible mixture and a manifold 46 for the outlet of exhaust gases with corresponding openings for the passage of the combustible mixture 47 and for the outlet of exhaust gases 48. In the heads of cylinders 2, 3, 4, 5 holes 49 are made for the spark plug and the ignition contact 50.

The engine works as follows.

Starting the engine. Voltage is applied to the winding 17 of the stator 16 and the generator, operating in the mode of a linear electric motor, moves the pipe 14, on which permanent magnets 15 are fixed and balls 21, 22 are installed, together with pistons 6, 7, 8, 9 and rods 10, 11, 12 , 13 to the right. In this case, the balls 21, 22, moving along the groove 20, rotate the shaft 18, mounted on the housing 1 on the bearing 19, counterclockwise (when viewed from the left end of the engine). Together with the shaft 18, the disc 23 rotates, which by the inlet protrusion 25 hits the roller 40 of the rod 39 of the intake valve 31 of cylinder 2. The intake stroke begins. So until the protrusion of the inlet 25 comes off the roller 40 of the rod 39 and the inlet valve 31 closes. When a voltage of a different polarity is applied to the stator winding 17, the pipe 14, together with the pistons 6, 7, 8, 9, moves to the left and in the piston 6, the compression stroke begins until the ignition lug 27 of the disc 23 closes the ignition contact 50 and the voltage is applied to the spark plug 41. The power stroke begins. The engine is running.

Cyclogram of engine operation (Fig. 7).

The movement of pistons 6, 7, 8, 9 of cylinders 2, 3, 4, 5 from left to right (Fig. 7 a, b). Balls 21, 22, moving along the groove 20, turn the shaft 18 counterclockwise (as viewed from the left end of the engine) from 0 ° to 90 °.

Cylinder 2. The disc 23 runs over the inlet protrusion 25 onto the roller 40 of the rod 39 of the inlet valve 31 of cylinder 2. The INLET cycle begins. So until the protrusion of the inlet 25 comes off the roller 40 of the rod 39 and the inlet valve 31 closes.

Cylinder 3. All valves on cylinder 3 are closed. There is a COMPRESSION beat.

Cylinder 4. All valves on cylinder 4 are closed. The disk 23 is driven by the ignition protrusion 27 onto the ignition contact 50. The voltage is applied to the spark plug 43 installed in the hole 49. The OPERATING cycle begins.

Cylinder 5. Disc 24 is driven by the release protrusion 29 onto the roller 40 of the rod 39 of the exhaust valve 38 of cylinder 5. The EXHAUST stroke begins. So until the protrusion of the outlet 29 comes off the roller 40 of the stem 39 and the outlet valve 38 closes.

The movement of pistons 6, 7, 8, 9 of cylinders 2, 3, 4, 5 from right to left (Fig. 7 c, d). Balls 21, 22, moving along the groove 20, turn the shaft 18 counterclockwise (as viewed from the left end of the engine) from 90 ° to 180 °.

Cylinder 2. All valves on cylinder 2 are closed. There is a COMPRESSION beat.

Cylinder 3. All valves on cylinder 3 are closed. The disc 24 runs over the ignition contact 50 by the ignition lug 30. Voltage is applied to the spark plug 42 installed in the hole 49. The OPERATING cycle begins.

Cylinder 4. Disc 23 runs over by the protrusion of the outlet 26 onto the roller 40 of the rod 39 of the outlet valve 37 of the cylinder 4. The EXHAUST stroke begins. So until the protrusion of the outlet 26 comes off the roller 40 of the stem 39 and the outlet valve 37 closes.

Cylinder 5. Disc 24 runs over the inlet protrusion 28 on the roller 40 of the rod 39 of the inlet valve 34 of cylinder 5. The INLET cycle begins. So until the protrusion of the inlet 28 comes off the roller 40 of the rod 39 and the inlet valve 34 closes.

The movement of pistons 6, 7, 8, 9 of cylinders 2, 3, 4, 5 from left to right (Fig. 7 e, f). Balls 21, 22, moving along the groove 20, turn the shaft 18 counterclockwise (as viewed from the left end of the engine) from 180 ° to 270 °.

Cylinder 2. All valves on cylinder 2 are closed. The disc 23 runs over the ignition contact 50 with the ignition protrusion 27. Voltage is applied to the spark plug 41. The RUNNING cycle begins.

Cylinder 3. Disc 24 runs over by the protrusion of the release 29 on the roller 40 of the rod 39 of the exhaust valve 36 of the cylinder 3. The EXHAUST stroke begins. So, until the protrusion of the outlet 29 comes off the roller 40 of the rod 39 and the outlet valve 36 closes.

Cylinder 4. Disc 23 runs over the inlet protrusion 25 onto the roller 40 of the rod 39 of the inlet valve 33 of cylinder 4. The INLET cycle begins. So until the protrusion of the inlet 25 comes off the roller 40 of the rod 39 and the inlet valve 33 closes.

Cylinder 5. All valves on cylinder 5 are closed. There is a COMPRESSION beat.

The movement of pistons 6, 7, 8, 9 of cylinders 2, 3, 4, 5 from right to left (Fig. 7 g, h). The balls 21, 22, moving along the groove 20, turn the shaft 18 counterclockwise (as viewed from the left end of the engine) from 270 ° to 360 °.

Cylinder 2. Disc 23 is driven by the release protrusion 26 onto the roller 40 of the rod 39 of the outlet valve 35 of cylinder 2. The EXHAUST stroke begins. So until the protrusion of the outlet 26 comes off the roller 40 of the rod 39 and the outlet valve 35 closes.

Cylinder 3. The disc 24 runs over the inlet protrusion 28 onto the roller 40 of the rod 39 of the inlet valve 32 of cylinder 3. The INLET cycle begins, and so on until the inlet protrusion 28 comes off the roller 40 of the rod 39 and the inlet valve 32 closes.

Cylinder 4. All valves on cylinder 4 are closed. There is a COMPRESSION beat.

Cylinder 5. All valves on cylinder 5 are closed. The disc 24 runs over the ignition contact 50 with the ignition lug 30. Voltage is applied to the spark plug 44. The RUNNING cycle begins. After the end of the working stroke, the motor returns to its original position.

The combustible mixture enters the engine through port 47 and manifold 45, and exhaust gases are removed through manifold 46 and port 48.

The cyclically repetitive pressure of the gases in the process of fuel combustion imparts a reciprocating motion to the piston group. During the reciprocating movement of pistons with rods and a pipe with permanent magnets fixed on it, located inside the stator and interacting with the stator windings induces an electromotive force in them. In essence, this is the principle of operation of a linear generator with a free piston, which generates electricity directly from the linear movement of the piston without intermediate mechanical links. The top dead center of the trajectory depends on the compression ratio and the rate of combustion of the fuel charge. In fact, the braking of the piston occurs due to the creation of a critical pressure in the chamber and the subsequent spontaneous combustion of the mixture. In a conventional internal combustion engine, each subsequent cycle is analogous to the previous one, thanks to the rigid mechanical connections between the pistons and the crankshaft. In linear motors, the cycle time and top dead center are floating values. The slightest inaccuracy in the dosage of the fuel charge or the instability of the combustion mode causes the piston to stop or strike one of the side walls. The electronic control system must control the movement of the pistons to ensure an optimal thermodynamic cycle, as well as the positioning of the pistons to prevent them from colliding with the cylinder heads. In the proposed engine, the role of piston positioning is performed by a shaft mounted on bearings, passing inside a pipe with permanent magnets, on the side surface of which a continuous groove of a sinusoidal profile is made - two protrusions and two depressions, along which spherical bodies installed on the inner surface are rolled during engine operation pipes, limiting the piston stroke of the upper and lower dead centers. In this case, the shaft itself acquires a rotational movement (one revolution in four cycles in each cylinder), which makes it possible to install discs on the ends of the shaft, which act as a gas distribution mechanism. Why is it made projections with sloping entrances and exits from them of the rollers of the inlet and outlet valves and the ignition contact. At any time in one of the opposite cylinders, a stroke of the working stroke passes, providing a reciprocating movement of the pipe with permanent magnets inside the stator winding. As a result of the positioning of the pistons, their collision with the cylinder heads is prevented, the friction between the moving parts is reduced, which generally increases the reliability of the engine.

In addition to increasing reliability, the use of the proposed engine leads to a simplification of its design and increased efficiency.

Claims (1)

A free-piston internal combustion engine with a linear generator, including spark plugs, a linear generator containing a stator winding, a valve timing mechanism at the ends of the cylinder, an air-fuel supply manifold and an exhaust gas manifold, characterized in that it includes four cylinders, in the heads of which the valves of the timing mechanism are installed and ignition contact, with two pairs of coaxial pistons, rigidly connected by rods to a pipe, on the outer side of which permanent magnets are fixed, and on the inner surface of the pipe there are spherical bodies and a shaft, mounted with bearings on the housing, passes through, while on the lateral surface of the shaft there is a continuous a groove of a sinusoidal profile, and at the ends of the shaft there are fixed disks of the gas distribution mechanism with projections for controlling valves and an ignition contact.

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